WESTWOOD (CBSLA.com) — The personal data of as many as 4.5 million people may have been affected by a “criminal” cyber attack on computer systems at UCLA, officials announced Friday.

A spokesperson for UCLA Health Sciences said there was “no evidence” that the attack discovered on May 5 compromised “any individual’s personal or medical information.”

An investigation began in October when UCLA Health staff noticed “suspicious activity.” The health system notified the FBI and hired private forensic computer experts to investigate the breach.

Officials say based on that ongoing investigation, hackers may have had access to certain parts of the UCLA network as early as Sept. 2014.

On Friday, UCLA Health released the following statement: “At this time, there is no evidence that the attacker actually accessed or acquired the personal or medical information maintained on the impacted parts of the UCLA Health network, but we cannot conclusively rule out that possibility.”

UCLA Health covers four hospitals – including Ronald Reagan UCLA Medical Center – and more than 150 primary and specialty offices around Southern California.

Dr. James Atkinson, Interim President and Associate Vice Chancellor of UCLA Health, told KNX 1070 NEWSRADIO school officials are currently working with federal investigators and have hired private computer forensic experts to secure UCLA’s network servers.

“We’re working with the Los Angeles office of the FBI, they have indicated to us that it was likely an overseas attack, although we have no other information than that,” said Atkinson, adding officials had not been informed exactly from which nation the attack originated.

In response to the attack, UCLA Health is offering for one year free identity theft recovery and restoration services, as well as a $1,000,000 insurance reimbursement policy and additional healthcare identity protection tools to “potentially impacted individuals,” according to officials.

Individuals who believe they may have been affected by the attack were urged to call ID Experts at 877-534-5972 or visit MyIDCare.com. The deadline to enroll is Nov. 6.

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